This application is based upon and claims priority of Japanese Patent Application No. 09-329106, filed Nov. 28, 1997, the contents being incorporated herein by reference.
The present invention generally relates to an electrical connecting mechanism for a semiconductor device and other electrical elements and more particularly to a connecting device for electrical connection to an IC package in which many pins are arranged with a fine pitch, or a high speed, high frequency IC, such as a bare chip, wafer or other electrical element.
A contactor, such as a probe pin, has generally been used as a device for electrical connection to a semiconductor device and other electrical elements, particularly for testing purposes.
FIG. 1 is a diagram showing a structure of a probe pin in the related art. The probe pin shown in FIG. 1 includes a metal tube or pipe 200, a coil-shape spring 201, a metal end piece 202 and a terminal portion 203. The coil-shape spring 201 is provided within the metal pipe 200 and the metal end piece 202 is spring-biased in the upward direction of the drawing by the spring force of the coil-shape spring 201. The metal end piece 202 is provided to establish an electrical connection with an external electrode of a semiconductor device as the object of the test and the spring force produces a contact pressure between the metal end piece 202 and the external electrode. The terminal portion 203 is connected to testing equipment for testing the semiconductor device.
In the probe pin shown in FIG. 1, when the metal end piece 202 is in contact with an external electrode of the semiconductor device, a current flows to the terminal portion 203 via the metal tube or pipe 200 from the metal end piece 202. Therefore, the probe pin itself must be formed in a fine structure in order to provide many of these pins arranged to correspond with an IC package with many external electrodes arranged in a fine pitch. However, since the probe pin has a comparatively complicated structure, it is difficult to manufacture a fine probe pin. Moreover, even if such a fine probe is formed, it becomes very expensive.
Therefore, a probe pin as shown in FIG. 2 tends to be used recently. The probe pin of FIG. 2 includes a guide plate 210, a plurality of holes 211 provided in the guide plate 210 and a plurality of coil-shape springs 212 inserted into the holes 211. One end of the coil-shape spring 212 to be used as a contactor is placed in contact with an external electrode of a semiconductor device, while the other end of the spring 212 is connected to a testing apparatus. This type of probe pin is formed in a simplified structure and therefore many coil-shape springs 212 can be arranged with a fine pitch.
In the probe pin having the structure shown in FIG. 2, a current is transferred via the coil-shape spring 212. If a certain turn of the coil-shape spring 212 is not kept in contact with the next single turn, a current is transferred through a spiral path of metal wire of the coil-shape spring. Therefore, a problem arises that resistance and inductance become large.
In the case of the structure of the probe pin shown in FIG. 2 where a certain turn of the coil-shape spring 212 is in contact with the next single turn in many areas, resistance and inductance can be lowered. However, in this case, when the coil-shape spring 212 is compressed by a contact pressure from the external electrode, the contact condition of a certain turn and the next single turn changes, thereby resulting in a delicate change of a current transfer route. Therefore, a problem arises that fluctuation is generated in the current transfer characteristic in the contact condition.
It is therefore an object of the present invention to provide an electrical connecting device having an excellent and stable current transfer characteristic.
It is a further object of the present invention to provide an electrical connecting device that has a simplified structure, that can be readily mass-produced, and that can be arranged in a fine pitch.
It is a further object of the present invention to provide a method of testing a semiconductor device under a condition of an excellent and stable current transfer characteristic.
Objects of the invention are achieved by an electrical connecting device comprising a contactor to electrically connect first and second electrodes and having a coil-shape spring, and a transformable conductive member extending in a compressing direction of the coil-shape spring, wherein one end of the conductive member is pressure contactable with the first electrode and the other end of the conductive member is pressure contactable with the second electrode to electrically connect the first and second electrodes when the coil-shape spring is compressed; and a guide plate having a through hole in which the contactor is positioned.
A current transfer path may be shortened and low resistance, low inductance and stable electrical transfer characteristic may be realized, and a contact pressure may also be generated with a coil-shape spring by establishing the electrical connection between the first electrode and second electrode via the conductive member in place of the coil-shape spring. Moreover, for electrical connection to a semiconductor device where many pins are arranged with a fine pitch, it can be realized easily that the electrical connecting device can have a plurality of through holes in the guide plate provided with a fine pitch and a plurality of corresponding contactors can be inserted thereto and thereby a low price and high performance electrical connecting device can be provided.
Further objects of the invention are achieved by a method of testing a semiconductor device comprising: loading a semiconductor device having a first electrode to an electrical connecting device, the electrical connecting device having a contactor with a coil-shape spring, a transformable conductive member extending in a compressing direction of the coil-shape spring, wherein one end of the conductive member is in contact with the first electrode of the semiconductor device and the other end of the conductive member is in contact with a second electrode to electrically connect the first electrode and the second electrodes when the coil-shape spring is compressed, and a guide plate having a through hole in which the contactor is positioned; connecting test equipment to the second electrode of the electrical connecting device; executing a test to the semiconductor device through the second electrode; and removing the semiconductor device from the electrical connecting device.
Since the stable and excellent electrical transfer characteristic can be provided via the conductive member, high precision testing of semiconductor devices can be achieved and deterioration of an electrical signal for testing can be prevented.